Instead of asking when you'll incorporate virtualization into the data center, the question is how you're going to manage a combined physical and virtual environment.
It's an important consideration. Because server virtualization makes it so easy to spin up a guest operating system to run an application, and because you can reduce the number of physical servers you have to maintain, it's tempting to think that virtualization makes the IT environment less complex.
It doesn't. In fact, the ease with which VMs can be created may actually lead to problems around VM sprawl. All the barriers to provisioning physical servers in the old deployment model--purchase approval, build requests, network connectivity, physical reviews--can be leapfrogged by a zealous server admin responding to a business exec's demands. With just a few clicks and a minimum of configuration info, you can deploy a new VM for a development team or business unit. Such quick provisioning will make both IT and the business happy, but without oversight, these VMs can be easily forgotten. And orphaned VMs still consume server and network resources and may become the entry point for an enterprising intruder.
And sprawl is only the tip of the iceberg. Every VM brought online requires a proper allocation of resources, from I/O to storage. The hypervisor, guest OS, and apps will need patches and software upgrades.
And lest you forget about this quarter's visit from your friendly neighborhood auditor, virtualization isn't a magic wand that makes your organization's compliance and security policies disappear. Quite the opposite. A virtual environment may require additional oversight. That's because the hypervisor is yet another software layer that can be exploited, and VMs can communicate with one another without that traffic passing through your carefully constructed security and packet inspection systems.
And given the ease with which a virtual machine can move from one physical host to another, just keeping track of where a VM actually lives can be tricky.
The fact is, VM management tools are crucial for success in large virtualized environments. Without a management framework, organizations may find that their virtual infrastructures expose them to a variety of risks, from data loss and unauthorized exposure to compliance failures to application outages brought on by unbalanced VM provisioning.
This compelling business case prompted us to look at virtualization management tools for our latest Rolling Review. We'll test tools for controlling multiple host servers and their corresponding guest virtual machines. That includes guest creation, virtual network resource management, physical-to-virtual migration and deployment tools, automation capabilities, reporting, and security.
We've engineered a set of real-world tests to follow the life cycle of a virtual machine, with upgrades, patches, and migrations tossed into the mix. We'll see what kind of disaster recovery and high availability can be rigged up without spending big bucks. We will purposely engage in bad behavior to test governance and security policies. We will unplug running hosts and tell you what you can expect. And we'll look at whether small and midsize IT shops can get by using the basic management tools that come bundled with the hypervisors from Citrix, Microsoft, and VMware.
For large shops that must have (and can afford) full-fledged management packages, we'll run the same gamut of tests on these vendors' top-shelf management packages to see exactly how much bang you'll get for your bucks. We'll start with Microsoft's Hyper-V and its System Center Virtual Machine Manager. This Rolling Review will also put Citrix XenServer with Essentials through its paces, as well as VMware's vCenter Server management offerings.
In addition, we'll test a third-party management product that can handle a heterogeneous hypervisor environment. While it's true that VMware is the most widely deployed virtualization platform, we expect that organizations will be pulling away from a single-vendor strategy. For instance, while Microsoft has been slow out of the virtualization gate, Hyper-V can leverage the overwhelming installed base of Windows 2008 servers to gain a virtual foothold in the data center.
Meanwhile, data center consolidation, business acquisition, and the influx of private and public cloud infrastructures all open doors to a heterogeneous environment. Whether it's part of a corporate strategy to build out a multivendor hypervisor platform, or because a few guys in the data center started playing with Xen in their spare time and things grew from there, it's probably inevitable that your enterprise will include a variety of VM flavors.
How It All Adds Up
Finally, the series will wrap up with our take on the overall state of virtualization management. We'll provide a cost estimate for equivalent functionality across vendors, including licensing. We'll also compare the merits of the vendors we tested and suggest the tools that may be best suited for different organizational needs.
Our virtualization test lab will model a single-site enterprise; all testing and failover exercises will be LAN- and SAN-based, with no remote locations or externally hosted cloud hardware/software service concerns.
It's clear that server virtualization disrupts conventional data center management. Organizations eager to embrace the benefits of this technology must be prepared for the disruption. This review will attempt to capture the real-world experience of living with--and managing--a complex virtualized infrastructure.
Joe Hernick covers virtualization, storage and other topics for InformationWeek. Write to us at [email protected].